The invention concerns surgical apparatus and techniques, and particularly relates to microsurgery, for example involving closure of blood vessels of about very small size, usually done under a microscope, or endoscopic repairs, or repairing vessels difficult to access, for example in a deep recess or hole permitting only a narrow tunnel of access.
Microsurgery, such as in plastic and reconstructive surgery, neurosurgery, replantation of limbs and appendages, hand surgery, endoscopic and arthroscopic procedures, often involves the need to suture or otherwise close wounds on extremely small tissues, including blood vessels of 2 mm external diameter and smaller. The very small vessels often need to be united or reunited together, in a procedure known as vascular anastomosis. Sometimes a large number of these anastomoses are required.
In small vessels it is usually undesirable to employ suturing, because suturing invades the interior lumen of the vessel and can cause problems of restricting blood flow and promoting clotting in the lumen.
For these reasons implements have been developed for applying very small non-penetrating clips to the walls of blood vessels. Some of these clips and application procedures are shown in Kirsch U.S. Pat. Nos. 4,586,503, 4,733,664 and 4,929,240, and these patents are incorporated herein by reference. In addition, an implement called VCS Clip Applier System is marketed by Auto Suture Company, a division of United States Surgical Corporation of Norwalk, Conn. The VCS Clip Applier has three different sizes of stems, and of clips dispensed and secured by the tips of those stems, including a small size for microsurgery applications on vessels of 2 mm external diameter and under. The VCS Clip Applier is manual and one-handed in operation. The surgeon carefully places the tip of the stem, which is forked and fed by a magazine of clips, at a position where the C-shaped clip, when applied, will engage in non-penetrating relationship against two everted layers of tissue. When the clip is dispensed it is squeezed inwardly, deforming the clip to a smaller size. To do this the surgeon squeezes together two thumb/finger wings extending out from opposite sides of the tool's handle near the tip end of the handle; this squeezing motion is effective to slide a linkage piece in the stem, causing, at the tip of the stem, inward clamping and dispensing of the clip. In a longitudinal split or line of juncture on a blood vessel or between blood vessels to be joined, the VCS Clip Applier is used to apply the clips closely and accurately together for hemostasis. The clips are left in place and need not be removed.
Particularly in the smallest version of the VCS Clip Applier, useful on blood vessels of 2 mm in external diameter and smaller, there is a problem in maintaining the stem tip steadily in position while squeezing the wings of the handle to install a clip. This is done under the microscope, and often it is difficult to apply a clip accurately. Even if the surgeon has a very steady hand, the requirement of muscle contraction to squeeze inwardly on these handle wings almost inevitably causes some small movement at the tip of the clip applier stem, at the very instant of clip application. The result is an inaccurate application of clips.
Another problem arises in use of the VCS Clip Applier, even the medium or large versions, in an awkward location such as a deep recess forming a very narrow access hole where stitches could not be made and the elongated clip applier is needed. Sometimes the narrow access does not allow the required squeezing of the thumb/finger wings, because of the excessive forward location of those wings.
A solution to these difficulties is provided by the invention described below.